Rewrite ${((7^{-8})(3^{9}))^{-8}}$ in the form ${7^n \times 3^m}$.
Solution: ${ ((7^{-8})(3^{9}))^{-8} = (7^{(-8)(-8)})(3^{(9)(-8)})} $ ${\hphantom{ ((7^{-8})(3^{9}))^{-8}} = 7^{64} \times 3^{-72}} $